Magnetically actuated door seal

Abstract

An automatic door seal seals the gap between the lower edge of a door and a threshold. The seal is magnetically actuated so as to move downward into sealing engagement with the threshold when the door is closed and raises out of engagement when the door is opened. A transmission assembly converts horizontal movement from the magnetic force into vertical movement for the seal. Springs provide a reset force when the magnetic force is eliminated so as to retract the seal strip whenever the door is moved from the closed position.

What is claimed is: 
     
       1. A self-lifting sealing apparatus for a bottom edge of a door and a threshold of a door frame, comprising:
 a holder with a downward opening and mounted in a channel in the bottom edge of the door between interior and exterior surfaces of the door; 
 a magnetically actuated transmission assembly mounted in the holder; 
 a first magnet at one end of the transmission assembly; 
 a second magnet mounted on the door frame; 
 a sealing strip extending downwardly from the. transmission assembly; 
 wherein the transmission assembly moves automatically in response to an absence of a magnetic force between the magnets to a first horizontal position as the door is partially opened away from the door frame causing the sealing strip to move into a raised position within the holder and moves automatically when the magnetic force is present between the magnets to a second horizontal position after the door is closed causing the sealing strip to move into a lowered position below the holder. 
 
     
     
       2. The self-lifting sealing apparatus of  claim 1  further comprising a first reset spring to exert a reset force on the transmission assembly opposite the magnetic force. 
     
     
       3. The self-lifting sealing apparatus of  claim 2  wherein the first reset spring urges the sealing strip toward the raised position. 
     
     
       4. The self-lifting sealing apparatus of  claim 2 , further comprising a second reset spring to exert an upward pull force on the sealing strip. 
     
     
       5. The self-lifting sealing apparatus of  claim 2  wherein the transmission assembly includes a horizontally slidable rod extending through the first reset spring and having the first magnet mounted on the rod. 
     
     
       6. The self-lifting sealing apparatus of  claim 5  further comprising swing arms having upper ends pivotally connected to the rod and lower ends supporting the sealing strip. 
     
     
       7. The self-lifting sealing apparatus of  claim 1 , wherein the transmission assembly comprises a transmission rod, a batten bar, and swing arms hinged to the transmission rod and the batten bar. 
     
     
       8. The self-lifting sealing apparatus of  claim 7 , wherein the transmission rod is connected to the first magnet through a threaded connection. 
     
     
       9. The self-lifting sealing apparatus of  claim 8 , wherein the transmission rod slides horizontally within the holder. 
     
     
       10. The self-lifting sealing apparatus of  claim 1  wherein the door has opposite first and second vertical edges, and the door is hinged along the first edge, and the first magnet is adjacent the second edge. 
     
     
       11. A method of sealing a gap between a lower edge of a door mounted in a door frame and a threshold of an entryway, the door having a pivot edge hinged to the door frame and an opposite edge adjacent the door frame when the door is closed and the door having a seal mounted in a recess in the lower edge of the door, the seal being movable between a raised position when the door is opened and a lowered position when the door is closed, the method comprising:
 automatically moving the seal to the lowered position by a magnetic force between a first magnet in the opposite edge of the door and a second magnet in the door frame after the door is closed, and automatically moving the seal to the raised position by a spring force when the magnetic force is absent between the first and second magnets after the door begins to pivot open with the opposite edge moved away from the door frame. 
 
     
     
       12. The method of  claim 11  wherein the movement of the seal is generated by a horizontally moving transmission assembly. 
     
     
       13. An automatic door seal for sealing a gap between a lower edge of a door mounted in a door frame and a threshold of an entryway, the door having a pivot edge hinged to the door frame and an opposite edge adjacent the door frame when the door is closed, the door seal comprising:
 a seal mounted in a recess in the lower edge of the door and being automatically movable between a lowered position when the door is closed and a raised position when the door is open; 
 magnets mounted in the door and in the door frame to move the seal to the lowered position in response to a magnetic force between the magnets; 
 a spring attached to the seal to move the seal to the raised position; 
 the seal being automatically moved to the raised position when the magnetic force between the magnets is absent as the door begins to pivot open and automatically moved to the lowered position when the magnetic force between the magnets is present after the door is closed. 
 
     
     
       14. The automatic door seal of  claim 13  further comprising a transmission assembly connected to the seal and being movable horizontally in response to alignment and misalignment of the magnets so as to move the seal between the raised and lowered positions. 
     
     
       15. The automatic door seal of  claim 14  wherein the transmission assembly is mounted in the recess in the lower edge of the door. 
     
     
       16. The automatic door seal of  claim 13  wherein the spring is in the recess in the lower edge of the door to bias the seal to the raised position.